This invention relates to a mailing system, and more particularly to a digital mailing system incorporating a modular design.
Value dispensing systems are apparatus which dispense an indication of value. Examples of such value dispensing systems are postage meters, tax stamp machines, lottery vending machines, and admission ticket dispensing machines. With regard to postage meters, the indication of value printed, on a mailpiece or mailing label, is a postal indicia. The postage meter can be a stand-alone type postage meter containing, within a single securely sealed housing, accounting structure to account for the value of the postage dispensed by the meter and the total amount of postage funds added to the meter. In conventional stand-alone postage meters, the accounting structure is mechanically coupled to the printing mechanism which prints the postal indicia. Moreover, both the accounting structure and the printing mechanism are contained in the securely sealed housing except for that portion of the printing mechanism which necessarily extends out of the housing to print the postal indicia. The sealed secure housing had conventional mechanical security devices, such as sealed screws, which would permit a visual indication that tampering of the postage meter had occurred if the seals were broken. Accordingly, the maintenance and repair of the postage meter had to be done by a certified technician to ensure that once the securely sealed housing of the postage meter was opened up and the maintenance and/or repair completed, the housing was resecured with the appropriate mechanical security devices. This complex procedure added to the downtime and repair cost of a broken meter.
In addition to stand-alone postage meters, there are mailing systems which are a combination of a postage meter removably mounted on a mailing machine (also referred to as a base). The mailing machine provides the necessary structure for moving the recording medium (such as envelopes and tapes) upon which the postal indicia is to be printed, from a feeding position to the postage meter printing device. In the simplest mailing machine, only a recording medium feeding mechanism is included. In more sophisticated mailing machines, known structure is provided along the mailpiece feed path to accomplish additional functions such as singulating individual envelopes, moistening envelope flaps, and opening envelope flaps, all of which typically occur prior to the envelopes being fed and presented to the postage meter printing mechanism for printing of the postal indicia. In these conventional mailing systems (mailing machines in combination with postage meter), the accounting structure of the postage meter is mechanically coupled to the postage meter printing mechanism and both are contained in a securely sealed postage meter housing.
With the advent of new printing technologies, such as ink jet printing, it has been proposed to provide postage meters with ink jet printers. Additionally, since the ink jet printers are electronically versus mechanically driven, the postage meter accounting circuitry can be mechanically decoupled from the printing mechanism since only an electrical communication between the two is required. Moreover, new ink jet printing technology has, for example, permitted the use of smart cards as the structure for securely housing the accounting circuitry of the postage meter, which cards are referred to as smart card meter vaults. The smart card vault is removably placed into a conventional smart card receptacle mounted in a secure postage meter housing. The secure housing contains the postage meter printer together with other circuitry for performing additional meter functions such as communicating through a postage meter display and keyboard with a postage meter operator and controlling the printer motor or motors which move the printer as desired. This particular smart card structure is described in U.S. Pat. No. 4,900,903 issued to Wright, et al. on Feb. 13, 1990. In the aforementioned Wright patent, the printing mechanism includes, a microprocessor unit which controls the printing mechanism. However, because the printing mechanism and the smart card vault communicate via an unsecure communications link, security becomes an issue in that it is possible to drive the printing mechanism to print an indicia without accounting for the postage dispensed by tapping into the unsecure communications link. In an attempt to solve the security problem, the Wright structure ensures that the microprocessor unit for the printing mechanism will not operate the printing mechanism to print the postal indicia until a mutual authentication handshake has occurred between the smart card vault and the printing mechanism microprocessor unit. Moreover, in order to provide additional security, the microprocessor unit is formed integrally with the printing mechanism and is embedded in epoxy or the like so that it cannot be physically accessed without destroying the microprocessor unit and also the printing mechanism. Accordingly, the Wright postage meter, like the previously discussed devices, requires some type of secure mechanical protection for the printing mechanism of the postage meter. Accordingly, if the printhead microprocessor unit in the Wright apparatus is not operating properly the whole printing mechanism must be changed at a significant cost to the user.
Due to the strict security requirements of postage meters, conventional mailing systems have included the postal indicia printing mechanism as part of the secure postage meter and not as part of the mailing machine. In the United States, where postage meters can only be rented, a customer can buy a mailing machine but must still rent a postage meter to have a complete mailing system. In order to potentially reduce postage meter rental costs, it is desirable to include the printing mechanism as part of the mailing machine so that only a meter vault needs to be rented versus a meter vault/printer combination.
Accordingly, what is needed is a mailing system including accounting and printing modules which are mechanically decoupled from each other but which communicate in a secure manner. Moreover, the overall mailing system design should be modular to include individual removably mounted functional modules which can be readily accessed and removed for repair.